1. Field of the Invention
This invention relates to heat-curable fluoropolyether rubber compositions which cure into products having good heat resistance, chemical resistance, solvent resistance, parting property, water repellency, oil repellency and low-temperature properties.
2. Background Art
Japanese Patent No. 2,990,646 (JP-A 8-199070) discloses a composition comprising (A) a straight-chain fluoropolyether compound having at least two alkenyl groups in a molecule and a perfluoropolyether structure in the backbone, (B) an organosilicon compound having at least two H—SiOSi structures in a molecule, and (C) a hydrosilylation catalyst, which cures into parts having a good profile of heat resistance, chemical resistance, solvent resistance, parting property, water repellency, oil repellency and low-temperature properties.
However, when the crosslinking method applied to the fluoropolyether composition is a catalytic reaction like hydrosilylating reaction, there is a possibility of catalyst poisoning to inhibit curing. Catalyst poisons in the hydrosilylating reaction include sulfur compounds and amines, which are frequently employed as additives to customary synthetic rubbers. If the fluoropolyether composition is worked on the same rolls or molds as used in the processing of such other synthetic rubbers, there is a possibility that the composition fail to cure on account of the catalyst poisons left on the rolls or molds.